.image-box {
    cursor: pointer;
    position: relative;
}

.down-load {
    display: none;
    position:absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,.4);
}

.image-box:hover .down-load {
    display: block;
}

